If you are in a rush and don't have time to load the model into 3D, we get it, so we've designed a quick way for you to reply to comments and markup comments without the need to load into 3D.
When you are inside your project, simply click onto the thumbnail of the image, don't click the orange 3D icon on the bottom right of the thumbnail, just the thumbnail.
Once you click on the thumbnail, it will lead you directly into the review page. All the comments are shown in the discussion panel on the right side of the screen. To reply, simply starting typing in the dialogue box below. You can also edit an existing comment by hovering above the existing comment and click "Edit" when the sign appears.